Biomass–Water Interaction and Its Correlations with Enzymatic Hydrolysis of Steam-Exploded Corn Stover

Abstract

Author: Biomass–water interaction is a main factor affecting the enzymatic hydrolysis process. The interactions between corn stover and water and their correlations with enzymatic hydrolysis performance were investigated. The peak height of the main water pool was lower, peak width at half-height was bigger, and T2 relaxation time was shorter in steam-exploded corn stover (SECS) than in untreated corn stover (UCS). The relations between the total peak area of water pools and the moisture content can be well expressed by exponential models. Steam explosion enhanced corn stover–water interactions due to an increase in specific surface area, pore volume, average pore diameter, porosity, and oxygen to carbon ratio. Small particle size strengthened UCS–water interactions while slightly weakening SECS–water interactions. In enzymatic hydrolysis, constrained water was released before 36 h, which was consistent with the increase in glucan conversion. The release of constrained water and increase in glucan conversion facilitated each other. Steam explosion enhanced the interactions between SECS and water (mainly bound water), which increased the accessibility of carbohydrates to enzymes. Therefore, the release of constrained water before 36 h and the increase in SECS–water interactions on the surface of SECS facilitated the enzymatic hydrolysis efficiency.